Next to obstacle avoiding robots, the most common beginner bot would be a line follower. I myself love line followers, and they are some of my favorite weekend builds. It's just so fun watching a little bot following little black line over and over, but that's just me :-). There are also many practical uses for line following on a robot. Simple fixed navigation, docking guides (i.e. finding a charging station) as well as competition and many other uses.
A basic line follower is not all that complicated in reality, and can be done with just one sensor, but for better results it's best to use at least three or more sensors - the old saying “The more the merrier” but only to a point! For me, anything past 16 is overkill for a normal line following function.
There are many ways to detect lines, infrared, normal light, cameras etc. In basic line following, you are looking for light and dark differences, in this case a black line on a white or light surface.
This little bot will use pre-made IR sensor based on the TCRT5000 IR Rx/Tx diode pair. This module is easy to mount and use. It’s also very inexpensive and can be found from many sellers on eBay and other online shops.
A line follower needs a good base as a starting point to build from, and for this bot I will use the Actobotics Runt Rover Sprout chassis. It’s has a great form factor for line following, and lots of mounting options. It is also very cost effective for budding robot builders. If you have another chassis already or prefer a different one, that will be fine as well and should not be a big problem.
The line follower we will build for this project will have three (3) sensors spaced about 5mm apart from each other. The controller that will be used is an Micro Magician Controller from Dagu, but an Arduino Uno or clone with sensor standard shield and some sort of motor controller should work with some code changes. I chose the Micro Magician because that's what I had on hand that matched this project best. It has a built-in motor h-bridge, male pins for sensors and power switch. It also has many other features.
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